I faced this situation many times before in China and I think it's really embarrassing for them and for you because they have to repeat their names many times and you still know that even if they repeat it a 100 times you'll either still not be able to pronounce it right or you'll forget it after a couple of minutes.
So to save up all the time and all the awkwardness involved I tend to ask if they have an English name since I know that most of the Chinese students do.
I tried to inquire why he chose this name and his answer was very simple: "because I like batman"
Somehow It wasn't really surprising for me because when I used to teach here in China I used to find all sorts of weird names that were so funny or didn't even exist.
Here's a list of some of the weird names I found here:
Dick (his reason was that he was big :s)
Error404 (probably she was never found :p)
And the list goes on and on, however what's more annoying is that they usually choose the same name. I've on my phone book 10 Amys, 6 Ambers, 3 Bills, 5 Candys, 7 Sherrys, 3 Karas and 4 Evas.
But anyway I learned that being in China is awesome, even the names can bring a smile on your face during your hardest times here.